


Things Truly Wicked

by kirstenlouise



Category: Sherlock (TV)
Genre: Dubious Consent, Frottage, Hand Jobs, Incest, M/M, Punishment, Semi-Public Sex, Sibling Incest, Sibling Rivalry, Underage Sex
Language: English
Status: Completed
Published: 2012-04-01
Updated: 2012-04-01
Packaged: 2017-11-02 20:37:37
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 1
Words: 2,436
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/373089
Author URL: https://archiveofourown.org/users/kirstenlouise/pseuds/kirstenlouise
Summary: <blockquote class="userstuff">
              <p>Sherlock has humiliated Mycroft for the last time.</p>
            </blockquote>





	Things Truly Wicked

**Author's Note:**

> Many thanks to my anonymous benefactor. Originally written for [this prompt](http://sherlockbbc-fic.livejournal.com/17487.html?thread=107294287&#t107294287) at sherlockbbc-fic. Substantial edits have been made.

Sunday afternoon tea is traditional, according to Mummy. Sherlock is of the opinion that ‘traditional’ is nearly always synonymous with ‘boring’, present circumstances not exempted. It’s an incredibly dull affair to begin with, forced politeness and conversation as lukewarm as the tea, made even duller by Mycroft’s insistence on prattling on about one of his lecturers---the one whose bed he’s been warming all term, undoubtedly. 

Nothing else quite explains the slight flush above Mycroft’s collar or his careful sidestepping of any pronouns that might prove too revealing.

Sherlock smirks over the rim of his teacup. It’s a man this time, then. Mummy will be _appalled_.

He’s still trying to decide whether the ugly, cheap-looking trinket Mycroft has pinned to his lapel is a gift from the lecturer or from a student who has yet to charm his (her?) way into Mycroft’s good graces---his bed is considerably easier to infiltrate, going by the number of equally tasteless trophies he’s kept over the years---when his thoughts are interrupted.

“The sugar, please, Sherlock.”

He glances between Mycroft and his mother, the both of them sitting stiff-backed in matching chairs. “Mummy, tell Mycroft to get his own sugar.”

“Don’t be petulant, dear. And do take your feet off the sofa,” she adds with a cluck of her tongue. “God only knows where _they’ve_ been.”

“Oh, I’m sure Sherlock is simply overcome,” Mycroft says, before Sherlock can get in a word. His smile is a familiar double-edged line of feigned pleasantness and subtle menace. “He’s forgotten his manners amidst all the excitement of having me home.”

“A family trait,” he returns, with a pointed look at Mycroft’s lapel-pin. Mycroft looks at him witheringly in response. It is the lecturer, then. _Got you._ “Mummy---”

“Sherlock, _don’t_.”

There it is---that tone. The one that says there will be consequences if he continues. As if. He’s much too old to be turned over anyone’s knee and Mycroft hasn’t been home long enough to accumulate any leverage against him. There’s only the experiment he’s running under his bed and the mold he’s growing on the windowsill anyway, and neither are grounds for serious disciplinary action.

Sherlock sets his tea on the table and clears his throat. “Mycroft is trying to sleep his way to an early professorship again.”

His deduction is greeted with silence, apart from Mummy’s sigh and the twin clink of teacups being set on saucers. Sherlock doubts that he’s made the wrong deduction---he’s more certain than ever that he hasn’t---but it’s immediately obvious that he’s misspoken when Mycroft only raises an eyebrow in his direction before leaning over the arm of his chair.

He whispers something Sherlock doesn’t catch, and then Mummy is sweeping out of the room without another word, leaving him alone in the sitting room with Mycroft.

“I hope you’re pleased with yourself,” Mycroft says, voice mild as he stands. “You’ve upset her again.”

Mummy will spend the rest of the evening shut up in her room, Sherlock knows, but the perfunctory glimmer of guilt can’t compare to the satisfaction of having gotten a rise out of his brother. He watches with vague interest as Mycroft folds his jacket over the arm of the chair and starts in on his shirtsleeves, rolling them to his elbows one after the other.

“There’s no sense in shooting the messenger, Mycroft.”

“Beyond that, you’ve humiliated me.”

“Please,” Sherlock says, eyes rolling. “As if this is the first---” Sherlock’s words catch in his throat as Mycroft seizes him by the arm and jerks him off of the sofa.

“This is the last time I will allow you to humiliate me,” Mycroft says, gaze unflinching. His face is utterly calm and all the more frightening for it. For the first time, Sherlock feels the very real grip of fear, like hot iron striking his belly. “Do you understand?”

Sherlock swallows the lump in his throat. “You’re hurting me.”

It’s his pride that’s wounded more than anything else, but he doesn’t like the clench of his brother’s hand on his arm or the way his blood is beginning to rush in the wrong direction. His limbs are dragging him down, heavy and sluggish with heat that seems to be emanating from Mycroft’s hand.

The ugly twist of Mycroft’s mouth says that he knows something Sherlock hasn’t quite figured out, like why his hand is burning Sherlock’s upper arm like a cattle brand. He doesn’t trust that look at all.

“Let me go, Mycroft. I won’t do it again.”

“No,” Mycroft agrees. “You will not.” His eyes flick downward and Sherlock twists in his grip. It does him no good. Mycroft is stronger than him, for all his soft edges. Bigger. “You’re enjoying this, aren’t you? Being reprimanded.”

“No!”

“Then why is your _cock_ ,” Mycroft says, the syllable as startling and sharp as the crack of a whip, “straining the front of your trousers, brother dear?”

Adrenaline, Sherlock wants to say. Mycroft looms over him, too hot and too close, and his body is only responding to the fear of being cornered. The chemistry is painfully simple. His erection has nothing to do with Mycroft’s scolding, or the oily gleam in his eyes, or the silk-wrapped bite of his voice.

He’s fourteen. His cock doesn’t know any better.

None of the words make it past his lips before Mycroft releases him. Sherlock’s knees hit the edge of the coffee table on the way down, before he even realizes he’s lost his balance. His head is spinning. His knees hurt. His cock aches. He regards his brother through a haze, until Mycroft hauls him back to his feet and drops him on the sofa.

“Trousers down. I trust you’re capable of doing it yourself.”

“Lazy.”

“Expedient,” Mycroft corrects. This time his smile is one of indulgence. “Though I’ll help you along if need be.”

There’s nothing Mycroft can say that will make him voluntarily expose himself. Just to prove it, he sneers. “Do you intend to spank me, Mycroft?”

“Spank---god, no. Nothing so pedestrian.”

Sherlock resists the urge to scratch at the gooseflesh prickling his arms. It isn’t fear. It doesn’t fill him with dread or taste metallic in his mouth. It’s the way Sherlock imagines an insect with a rapidly descending collection pin aimed at its thorax might feel. He’s not sure what it is, but his cock is standing as stiff as ever and when Mycroft closes the distance between them, his knees lock in place.

His hands are electric on Sherlock’s hips, a shock burrowed directly under the skin. He jumps and Mycroft strokes down his trembling side with a soft murmur. 

“It’s all right, Sherlock. Everything is all right. You understand why I’m doing this, don’t you?” Mycroft asks, as he tugs the hem of Sherlock’s shirt free of his trousers. 

_Because you’re a pervert_ , Sherlock is tempted to respond. He watches Mycroft’s hands, still pinned to the back of the sofa by his steel-sharp eyes.

“Mummy has let you run wild, without discipline. It’s no wonder you’ve no sense of propriety.”

“You’re one to talk,” Sherlock says. His voice sounds small, even to his own ears. “Pervert.”

Mycroft only chuckles; he still ends up with his trousers down around his knees and the back of the sofa jammed up under his ribs as Mycroft flips him around.

“Shift your knees a bit wider,” Mycroft instructs. “Sherlock, I said---”

“Can’t.”

“Can’t or won’t?”

“Can’t,” he says for the second time. His bones have turned to jelly.

The hand between his thighs is firm and smooth, coaxing them apart until Mycroft can kneel between his calves. It occurs to Sherlock that he can’t close his legs. Mycroft is keeping them open. They’re flush now, crammed into the narrow space the sofa affords, with his cock wedged uncomfortably between his belly and the upholstery. Anyone could find them, Sherlock knows, but even that doesn’t make him go soft.

If Mycroft is a pervert, he can’t be far behind.

One of Mycroft’s hands snakes around his hip and tugs Sherlock back into his chest, bowing his back. It should be easy to anticipate. Predictable. _Boring_. It’s anything but. Mycroft takes him in hand and Sherlock jerks like a live wire.

He’s never had anyone else’s hand on his cock and even though his brain tells him it shouldn’t make any difference---identical stimulus, identical reaction---it does. Mycroft’s hand swallows up his cock, sure and quick. He tugs and twists so hard Sherlock can feel something pulling in his belly. It’s hardly punishment. It’s positive reinforcement for negative behavior. Surely Mycroft can appreciate the difference. 

Sherlock drops his head to the back of the sofa, mouth open in a moan. Mummy will be furious when she finds he’s drooled on the upholstery. There will be stains on the sofa cushions. He’s probably dripping down Mycroft’s fingers. More stains. Distantly, he realizes how absurd he’s being. They’ll have to burn the sofa and them with it if Mummy ever finds out what they’ve done on it, never mind the stains.

“You aren’t fucking me,” Sherlock says. It’s half a question, half denial of the heat at his back where Mycroft has lowered his own trousers. “You aren’t, Mycroft. I’ll tell Mummy if you---”

Mycroft claps a hand over his mouth. “Quiet, you insolent child.”

His fingers smell like sweat and skin-musk from pulling Sherlock’s cock. He could bite, sink his teeth into Mycroft and make him stop. Mycroft’s hand isn’t that tight a seal. He could still scream, even, if he wanted it to stop. If he wanted Mummy or the maid to find him like this, with his trousers around his knees, hunched over at exactly the right angle for Mycroft to push up inside him.

Instead, he licks Mycroft’s palm. He’s never tasted himself before. It’s salt, bitter. He licks again, not sure if he likes it or if it’s simply something to do. Mycroft starts to move at his back. It takes a couple rocks of his hips before Sherlock realizes that Mycroft is sliding his cock along the cleft of his arse. Not inside at all. He doesn’t get long to think about it before Mycroft has a hold of him again, jerking him with the hand Sherlock isn’t lapping at.

“You understand it now, don’t you,” Mycroft says, quietly, without ever stopping the movement of his hips. His hand drops away from Sherlock’s mouth. “Tell me you understand.”

“Yes,” Sherlock says, because ‘yes’ is as good an answer as any. He doesn’t understand, really, but he means it---‘yes’ he wants it and ‘yes’ he promises not to tell Mummy and ‘yes’ he’ll be a good boy if Mycroft wants to keep working his fist around Sherlock’s cock.

“Very good. We’ll make a fine, upstanding gentleman of you yet.”

“Unlikely,” Sherlock says, before Mycroft’s hand tightens too much for him to do anything but close his eyes and slump bonelessly against the sofa.

The way that Mycroft keeps rubbing over his hole with every pass is putting an itch under his skin. Sherlock doesn’t know if he wants it to stop or if he wants to tilt his hips and catch Mycroft inside him, no matter what he said before. His back and his arse are smeared sticky with precome and he isn’t at all sure that he doesn’t like it anymore.

“Stop fidgeting,” Mycroft says.

“Stop panting,” Sherlock counters. “I can hear you. Like a Hoover.”

Barely, and only because Mycroft has his lips on the spot below Sherlock’s ear, but he prefers to cling to the illusion that Mycroft is as strung out and desperate as he feels. He probably is, somewhere on the inside, but he’ll be damned if he’s about to show it and risk sacrificing the upper hand. Sherlock doesn’t know what they’re playing for anymore, but that doesn’t mean Mycroft has forgotten.

“You’re allowed to come, you know,” Mycroft says. “You’ll come for me, won’t you?”

His cock jumps in Mycroft’s hand, as if on cue. “You first.”

 

“Are we competing?”

“Aren’t we always?”

Mycroft gives a low chuckle before kissing his neck. It’s the first tender thing he’s done since they started, and somehow it affects Sherlock more than all the rest. Another kiss and he’s quaking. One more and it doesn’t matter that Sherlock is losing Mycroft’s game. He can’t remember any orgasm leaving him as breathless as this one, when he finally comes over Mycroft’s fingers and the back of the sofa. 

It’s its own sort of victory.

It doesn’t take long before Mycroft grunts and splatters Sherlock’s back with his own orgasm. It drips down the cleft of his arse, already wet. He clenches automatically at Mycroft’s fingers, smearing it into his skin for a brief moment before climbing off the sofa. His shirt is most probably ruined, as is the sofa, Sherlock imagines. 

It’s easier to think of their debauchery in terms of sofas and shirts than to think of what it means for him.

They dress and right themselves as best as they can. Mycroft rearranges the pillows on the sofa to cover up the wet spots while Sherlock watches.

“Mummy will find it.”

“Yes, I imagine she will,” Mycroft says. “But not by stumbling upon it.”

“You’re not going to tell her, Mycroft, you can’t.”

“On the contrary, _you_ are going to tell Mummy,” Mycroft says, brightly, as he rolls his sleeves back down and rebuttons his cuffs. “You will clean up, redress yourself, and then you will inform Mummy that you have been a very, _very_ naughty boy and that in the process of acting out, you ruined her antique sofa.”

“And if I refuse?”

“Then either Mummy or the maid will find it and you’ll be forced to explain regardless.”

It’s just like Mycroft, to set up circumstances he has no way out of and then present it like a choice, when he knows perfectly well that whatever Sherlock chooses, the results will be the same. He’s twice damned.

“Then I’ll wait. And I’ll blame it on you, you malignant hedonist.”

Mycroft frowns. “Oh, I’m terribly sorry, I forgot to mention. If you confess voluntarily, I’m willing to reward you for your honesty. I would so love to continue this little liaison. Later this evening, after dinner, shall we say?”

Sherlock watches him retreat, waiting until the clacking of Mycroft’s heels has faded from hearing before he collapses on the sofa. 

Making a deal with Mycroft, he decides, is not all that different to making a deal with the devil.


End file.
